In a message dated 8/24/02 2:08:10 AM Eastern Daylight Time, [email protected] writes:
> Why does "True SELV" require basic insulation > >between SELV and earth? > > > >What is the hazardous voltage source, and what > >is the current path through the body if that > >basic insulation should fail? > > > I believe (and I could be wrong) that it's a philosophy of keeping SELV intact under single fault conditions. If there's a single fault bridging mains and earth, then an SELV circuit is exposed to mains voltage unless there is basic insulation protecting it. Since it is estamited that close to 50% of the homes in the US have improperly grounded outlets, the earth connection itself is not taken into consideration as a reliable means of protection. In other words, for the purposes of the standard, an open earth connection is not considered a fault. Greg Galluccio www.productapprovals.com <A HREF="www.soundsurfr.com">www.soundsurfr.com</A> <A HREF="www.artistlaunch.com/soundsurfr">Soundsurfr At ArtistLaunch</A> <A HREF="http://www.artistlaunch.com/twominds";>Two Minds At Artistlaunch</A> <A HREF="http://www.mp3.com/soundsurfr";>Soundsurfr At MP3.com</A>
